The physical and electrical integrity of monolithic integrated circuit devices are routinely ascertained at various stages of the manufacturing process. Although such circuit devices may be individually tested, it is much more efficient to test them in groups. A burn-in test is typically the last test to which an integrated circuit (IC) is subjected following encapsulation in a plastic or ceramic package, and prior to packing and shipment. Some ICs are shipped as bare die (i.e., unencapsulated). However, even the bare die must be burned in, and this is usually accomplished by placing each bare die in a temporary package. The burn-in test usually involves imposing controlled electrical and thermal stresses upon a group of packaged IC devices (also referred to as packaged ICs) which have been loaded into sockets on a burn-in board (BIB) and placed in a controlled environment. Upon completion of the burn-in test, fully-functional, partially-functional and nonfunctional IC devices are identified, the IC devices are unloaded from the burn-in board, and ICs are segregated on the basis of functionality, with the fully-functional and partially-functional IC devices being loaded into carrier containers for subsequent transfer or storage. The nonfunctional IC devices are generally scrapped.
The manner and means by which packaged IC devices are loaded and unloaded from a burn-in board or device-testing board (DTB) is the primary focus of this invention. In addition, a secondary focus of the invention is the manner and means by which the packaged IC devices are sorted and loaded into transport media.
Various devices and mechanisms have been developed in the industry to insert packaged IC devices into the sockets on burn-in boards, extract packaged IC devices from those sockets once the burn-in operation is complete, and sort the extracted packaged IC devices. One typical tool used to insert packaged IC devices into and extract packaged IC devices from low insertion force (LIF) sockets on burn-in boards consists of a pair of controllable, opposed, gripping fingers which grip opposite edges of the packaged IC device and then operate on the package in a direction orthogonal to the surface of the burn-in board so as to insert or extract the packaged IC device. SMC Pneumatics Corp. manufactures an "MHP Series" of pneumatically-operated gripping devices that are used to implement certain embodiments of the instant invention. Dual-in-line packages (DIP) and small outline J-lead packages (SOJ) are common IC packages which may be handled by such gripper devices. Pneumatic holding devices are used to load and unload zero-insertion-force sockets, and such holding devices are used to implement other embodiments of the instant invention.